Krah pipe (HDPE winding pipe) is a flexible pipe. The Krah pipe has the advantages of good connection tightness, strong anti-settlement ability and long comprehensive service life, and has been rated as the key promotion of green environmental protection pipe products by the ministry of municipal construction of China.

Krah Pipe product is an environmental protection and safe type of pipeline product, because of its high quality characteristics are widely used in all kinds of pipeline engineering projects, so, the demand for Krah Pipe is also increasing day by day, which makes the quality of the Krah Pipe on the market at random, is irregular.

HDPE/PP Gas Pipe systems with various stiffness classes which are designed for utility and industrial applications. HDPE Profile Pipe has gradually replaced the status of PVC-U Profile Pipe and become the main consumer pipeline.

The plastic (PEHD or PP) is melted in the main extruder:(1) (mostly black material to provide the required UV-resistance of the spiral pipe) and in the co-extruder (2) (mostly yellow material to provide the required bright, inspection friendly inside surface). In the melt distributor (3) the materia